This invention relates to devices for elevating a swimming pool cover above the rim of the swimming pool, particularly devices for elevating a flexible pool cover above the rim of an above-ground swimming pool that are adapted for ease of installation and removal.
Swimming pool covers are widely used by owners of swimming pools to shield the pools from dirt and other debris during times when the pools are not in use, as well as to discourage persons from entering the pool so as to protect against accidental drowning. However, swimming pool covers that are not elevated above the rim of the pool tend themselves to collect dirt, debris, water, snow and other matter and, accordingly, become difficult to remove without transferring the collected matter to the water in the swimming pool in frustration of the pool cover's purpose. In addition, swimming pool covers that are not elevated pose a risk of accidental drowning if anyone were to fall into water collected on the pool cover.
Conventional pool cover elevation devices and systems generally take one of two forms, each with significant limitations. One form elevates the pool cover by trapping a large volume of air below the pool cover. The air is trapped either by making the cover-to-pool connection air tight or by inserting a balloon, float or other air-trapping device below the surface of the pool cover. Such balloons, floats and air-trapping devices, once inflated, float on the water in the swimming pool, thereby elevating the pool cover above the water surface. In one variation, the air-trapping device elevates a central frame that supports the pool cover, which frame comprises a plurality of arms that are radially-disposed from the top of the air-trapping device and that attach to the rim of the swimming pool. Examples of the foregoing can be found in Brown U.S. Pat. No. 3,801,994, issued Apr. 9, 1974; Gannon U.S. Pat. No. 4,000,527, issued Jan. 4, 1977; Sorrentino U.S. Pat. No. 4,122,562, issued Oct. 31, 1978; and Phillips U.S. Pat. No. 4,790,037, issued Dec. 13, 1988.
This first form of conventional elevation system is subject to significant limitations. For example, over time and particularly during periods of cold weather, the air-trapping device tends to deflate, rendering it ineffective without maintenance. In some systems, the air-trapping device cannot be reinflated without removing the pool cover, which is especially burdensome in adverse weather conditions. In addition, in some cases the air-trapping device is installed by first partially draining and then refilling the swimming pool, a time-consuming and wasteful task. Moreover, such systems tend to be complex; accordingly, installation, maintenance and removal generally cannot be accomplished by hand, without tools and without expending a significant amount of time.
A second form of conventional elevation system relies on a central member from which a plurality of arms radiate in an umbrella-like fashion, instead of relying on a trapped volume of air. In one such system, the central support member is attached to the bottom of the swimming pool and projects vertically from that point of attachment to a position above the swimming pool rim. Each of the plurality of support arms is attached at one end thereof to the top of the central support member and at the other end thereof to the rim of the swimming pool. The pool cover is then supported by the assembly of central support member and support arms. An example of the foregoing can be found in Del Gorio, Sr. U.S. Pat. No. 4,951,327, issued Aug. 28, 1990.
This second form of conventional elevation device or system is also subject to significant limitations. For example, the system of the Del Gorio, Sr. patent generally comprises a large number of substantially rigid components that must be assembled by fixedly interconnecting the components to each other, adjusting their relative positions, and attaching the interconnected assembly both to the bottom of the pool and to the rim of the pool at a plurality of locations. Accordingly, the system's installation, maintenance and removal is relatively difficult and generally cannot be accomplished by hand, without tools and without expending a significant amount of time. Moreover, the central support member makes contact with the bottom of the swimming pool and, therefore, produces a risk of damage to the lining of the swimming pool.
Because the conventional approaches to elevating a pool cover each have inherent limitations, there accordingly is a need for an improved swimming pool cover elevation device.